Power-operated chuck.



i, UNITED STATES PATENT OFFICE.

WILLIAM L. MILLER, lOIE MADISON, WISCONSIN, .ASSIGNOR TO GISHOLT lMACHINE- COMPANY, OF `MADISON, WISCONSIN, A CORPORATION OF WISCONSIN.

POWEFOPERATED CHUCK `Speciiication of Letters Patent.

Application filed May 15, 1912. I Serial No.-697,398.

power-operated chuck'wherein the chuckingdevices 'are actuated in. either or both directions by fluid pressure acting upon a piston contained within a cylinder.

In most fluid pressure operated chucks, so far as I am aware, the cylinder and piston are mounted upon and rotate with the spindle, and employ a stationary valve for admitting motive fluid to one. or both sides of the piston.

One object of my invention i's to dispense Y with this rotary motor, and employl a nonrotary cylinder and piston in connectionA f l with a movable valve for admitting and exhausting the motive fluid.

Another object of the invention is to provide a construction which shall substantially eliminate the end thrust -upon the.

thrust bearings of the spindle4 so far as the action of the chuck-actuating mechanism is concerned.

A still further object of the invention is to provide a new and improved structure of chuck especially adapted to support hollow Work, such as a piston casting.

Theinvention, its mode of operation, and its advantagesrwill all be readily understood when considered in connection with the accompanying drawing illustrating` one practical embodiment thereof, in which- Figure 1 is an axial horizontal sec-tion, broken out between its ends, through a power-operated chuck embodying my invention; and Figs. 2 and 3 are cross-sectional details, enlarged on the lines 2 2 and 3 3, respectively, of Fig. 1.

Referring to the drawings, 5 designates a portion of the headstock frame of a lathe or like machine, and `6 and 7 the outer and inner bear-ings in which is journaled a hollow spindle 8, to the inner end of which is secured the chuck-head 9. The spindle 8 is provided, between the bearings 6 and 7, with suitable driving gear (not shoWn);/al1 d Secured to the outer end of the spindle 8 is a.

bushing 10 which forms a bearing for the outeren'd portion of a chuck-actuating member, here shown as a tube 11, that extends through the spindle 8 coaxially wth` the latter; said tube being threaded at its inner end into a bearing sleeve 1`1a that lits' .the bore of the chuck-head 9.

Supported on the outer end ofthe Aframe 5. by a series of studs 12, and coaxially dis- Y .posed relatlvely to spindle 8 and tube 11, is

a'cylinder comprising inner and outer "vlinder heads 13 and 14, respectively, and an intermediate cylindrical wall 15'that is conveniently cast integral with the inner cylinder head 13; the outer cylinder head 14 being secured lthereto as by screw-s 16. The cylinder" is mounted on the studs 12 with capacity for a slight end lmotion, for a purpose hereinafter disclosed. Within the -cylinder is a piston 17 provided-in its pe- 'gaging inwardly extending flanges20 and 21 fogmcd on the cylinder-heads 13 and 14, respectively, and equipped with' suitable packing 22 and 23. The cylinder heads 13` and 14 are formed with ducts 24 and 25, -respectively, leading to opposite sides of the piston from a valve-chest 26, in which latter is slidably mounted a' longitudinally movable valve 27. A supplyY pipe 28 for the motive fluid enters thevalve chest 26 .cen-

.ries of radial ports 34 and an end port 35,

and the exhaust chamber 31 has two series of radial ports 36 and 37. In the` position of the valve shown, motive fluid is` introduced to the left side of the piston through ports'33, chamber 29, ports 32 and duct 25; while motive fluid is exhausting from the opposite or right side of the piston through duct 24, ports 36, chamber 31 and ports 37. A

In'the'reversed position of the valve, mo-

tive fluid is supplied to the right-hand side of the piston through ports 32, chamber 29,

ports 33, -and duct 24, while the motive v Huid on the opposite or left side of the piston is exhausted through duct 25, ports 34, chamber 30, and end port 35.

Keyed en the tube 11 and lying within annular flange 44 radially opposite the collar 38 and just inwardly of the inner raceway 41; and the outer end of the piston hub 19 is internally threaded and receives adjusting nuts 45 and 46. The adjusting nut-s v39 and 40 are so set that normally the space between the inner nut 39 and the collar 38 v Slightly exceeds the full width `ofthe antifriction bearing; and the same is true of the adjusting nuts 45 and 46 relatively to the flange 44 and the anti-friction bearing.I all for a purpose hereinafter explained.

The inner end wall 13 of the cylinder is formed with a hub-like extension 47 having an external annular flange 48 that is mounted on the studs 12. Secured to the outer face of the flange 48 by screws 49- is a. keeper ring 50, the inner periphery of which extends some distance inwardly of the bore of the hub extension 47 forming an annular shoulder 51. The bushing 10 that is threaded into the outer end. of the spindle 8 vis of less diameter than the latter, thereby forming at the end of the spindle an annular shoulder 52 lying in substantially the.

same transverse plane as the annular shoulder 51. Screwed on to the outer end of the bushing 10 is a ring 53, the inner face of which forms an annular shoulder 54; and at the inner end of the bore of the hub extension 47 is a fourth annular shoulder 55. Between the bushing 10 and the hub extension 47, and confined endwise between the shoulders 51, 52 and the shoulders 54, 55 is another anti-friction bearing comprising race-ways 56 and 57, and interposed balls 58. The space between the shoulders 51 and 55 is slightly greater than the total width o'f the bearing; and the same is true .of the space between the shoulders 52 and 54.

59 and 60 designate the end thrust bearings of the spindle, located at opposite ends of the horizontal bearing 7.

1n the position of the parts shown, motive fluid admitted to the left side of the piston has forced the latter to the right. The piston thrust acts through the piston hub .19, rings 45 and 46, the anti-friction bearing 42, 43, 41, and collar 38, to force inwardly the tube 11, thereby actuating the ehucking devices at the opposite end o f the tube; while the re-action against the outer end wall 14 of the cylinder through the cylinder wall 15, inner end wall 13, hub extens1on 47, shoulder 51, anti-friction bearing 56, 58, 57, shoulder 54, ring 53, bushing 10, upon the spindle 8, tending to thrust the latter outwardly. When the valve 27 is reversed, the motive fluid acts upon the vright side of the piston, and the thrust of the piston is then through the flange 44, anti-triction bearing 41, 43, 42, and nuts 39 and 40, upon the-tube 11, forcing the latter outwardly, or in a direction to release the ohucking devices. There-action against the inner end wall 13 of the cylinder is exerted through the shoulder 55, anti-frictionbearing 57, 58, 56, and shoulder 52 ot' the spindle,

ltoreing the latter inwardly. During the inward thrust upon the chuck-actuating tube 11, the race-way 42 tends to remain stationary with the pistonfhub 19 by reason of its frictional engagement with nut 45, and the race-way 41 tends to turn by reason of its frictional engagement with the collar 38,; also the race-way 56 remains stationary by reason of its frictional engagement with the shoulder 51, and the race-way 57 tends to with the ring 53. Conversely, when the chuck-actuating tube 11 is forced outwardly, the race-ways 41 and 57 tend to remain stationary, and the race-ways 42 and 56 tend yturn by reason of its frictional engagement to turn with't-he spindle 8 and tube 11. By

reason of the fact that .the cylinder is not rigidly secured tothe headstoek frame, but is so mounted as to be capable of a slight endwise play relatively' to the headstoek frame, the outward and inward thrust upon the tube 11 counter-acts the simultaneous inward and out-ward thrust upon the spindle 8 thus relieving the thrust-bearings 59 and 60 'of the spindle of end thrust resulting from the action of the chuck-actuating mechanism.

In connection with the chuck-head and chuck-actuating tube 11, I have shown a novel chucking mechanism well adapted to support a hollow'structure, such as an engine piston, while the same is .being turned;

although it is to be understood thatt-hc fluid-pressure operated mechanism for actuating the chuck may be employed with any other chueking mechanism, including many of the various types now in common use.

Secured to the frontface otl the chuckhead 9 is a hollow mandrel 61 on which is adapted to be supported any hollow casting, such as the engine piston shown at 62.

Keyed within the inner end of the tube 11 is a wedge-block 63. One inclined face 64. of said wedge-block engages the inc-lined inner end 65 of a tube 66 that lies within and longitudinally of the mandrel 61: said tube 66 being normally urged outwardly by a spring 67. Lying within and coaxial with the tube 66 is a rod 68 having an inclined inner end 69 engaged by the other inclined 'face 70 of the Wedge-block 63. The rod 68 is normally urged inwardly or toward the wedge-block by a spring 71; and the lreduced outer end portion of the rod68 cx- 4tends through thelouter end of the tube 66 and the bore of' the outer end of the mandrel 61, and terminates in an inclined outer end 72. The outer end of the tube 66 is beveled, aS shown at 73, and engages the oblique inner-ends 74 of a series ofv radially disposed pins 75 -slidablyfmounted in suitable radial holes4 76 in the mandrel 61'. The outer inclined end 72 of the rod 68 engages the inclined inner end 77 of asimilar radial pin 78 slidably mounted in a radial hole 79 in the'outer end of the mandrel 61. The outer end' of said mandrel is further provided, on

its upper side, with a pair of serrated horns 80 (Fig. 3) and the tube 66 and rod 68 are held against rotary movement relatively to each other'and to the mandrel 61 by a key 81 extending through a vslot 82 in the tube 66 and into a Groove 83 in the rod, 68.

It will be evident from thel foregoing that when a piece of work, such as the piston easting"62, is chuckedfover the mandrel' 61,

v mechanism carried thereby, able chuck-actuating member 'within said Y'piston in said cylinder, -ing thrust connections the inward movement of the Wedge-block 63 by the power-operated mechanism hereinabove described, forces the radial pins 75 and 79 outwardly into holding engagement with the inner wall of the work 62,the outward movement of the pin 78 at the same time forcing the work into holding engagementwith the horns 80 ofthe mandrel, so that the work is securely supported on' the chuck mandrel. Upon the return movement of the tube 11, the wedge-block 63 is retracted, andthe springs 67 and 71 operate to release the grip of thepins and hornsi upon the work, allowing the latter tobe readily Withdrawn from the chuck mandrel.

AWhere other forms. of chucking devices are employed, the jaw-actuating members will, of course, be so connected withythe tube' 11 as to be actuated in their jaw-closing and opening movements by thejopposite move- `ments of the chuck-actuating member 11.

' I claim- 1. In a power-operated chuck, the combination with a headstock frame, andaalf'hollow spindle mounted therein, of chucking spindle, anon-rotary cylinder arranged coaxally with said spindle, a piston in said cyl- 1n erpistoii and said chuck-actuating member.

2. In a power-operated chuck, the combination with a headstock frame, and a hollow spindle mounted therein, of chucking mechanism Vcarried thereby, an ndwise movable chuck-actuating member within said spindle, a non-rotary double-acting cylinder arranged coaxially with said spindle, a

between said piston and said chuck-actuating member.

an endwis'e mov! and athrust connection` between said ,movement of the latter.

and oppositely act-4 p 3. In a power-operated chuck, the combii nation with' a headstock frame, and a hollow spindle mounted therein, of chucking mechanism mounted on one end of said spindle, a non-rotary cylinder arranged coaxially with the said spindle and supported on said headstock frame, an endwise movable chuck-actuating member within said spindle, a piston in said cylinder, and a thrust connection, including an anti-friction bearing, between said piston and said chuckactuating member.

4. In a power-operated chuck, the combination with aheadstock frame, and a hollow spindle mounted therein, of chucking mechanism mounted on one end of said spindle, a non-rotary cylinder arranged coaxially with said spindle and supported on said headstock frame with capacity for endwise movement relatively td, the latter, an endv'vise movable chuck-,actuating member within said spindle, a piston in said cylinder, a thrust connection, including an anti-frition bearing, between said piston and said chuck-actuating member, and a thrust connection including an anti-friction bearing,

connections, including an anti-friction bearing between said`piston and said chuck-actuating' member, and loppositely acting thrust connections, including an anti-friction bearing, between said cylinder and said spindle.u

6. The combination with a head-stock frame, anda hollow spindle mounted therein, of a chuck-head secured to. one end of said spindle, a lcored mandrel secured to the face of said chuck-head, radially disposed relatively to i pins slidably mounted in said mandrel, end-Y Y ,wisemovable means rwithin said mandrel for actuating said pins outwardly, spring means within said mandrel for retracting said pin-actuating means, and an lendwise movable member within said hollowspindle adapted to engage and actuate said pin-ac tuating 'means throughout the working \WILLIAM L. MILLER.

Witnesses: l l SAMUEL N. POND,

EDMUND G. INGnsoLL. 

